Many humans have impaired vision due to various refractive states of the eye. Throughout history many different methods and devices have been proposed and used in order to correct vision, with the most common being glasses and contact lenses.
Surgical techniques have also been proposed to treat numerous conditions of the eye by modifying one of the components thereof, for example the cornea or a lens. Relatively older techniques have been concerned with placing incisions in various portions of the eye in order to provide a desired result. More recently, these older techniques have been replaced with laser-based treatment methods that modify a portion of the eye without cutting or substantially weakening the eye.
Various methods and devices for modifying the cornea of the eye are disclosed in U.S. Pat. Nos. 4,724,522, 6,110,166, 6,635,051, 7,101,364, 7,189,224, 7,621,637 and U.S. Publications 2004/0054359 and 2005/0107775.
Regarding the use of lasers to correct various vision conditions, numerous devices and methods have been proposed.
U.S. Pat. No. 6,197,018 relates to presbyopia correction reportedly achieved by a tightening of the crystalline lens capsule. Applying laser energy to the pre-equatorial lens capsular membrane can reportedly increase the capsule tension without unwanted effects on the central clarity or on the refractive status of the eye. Wavelength selection, power, pulse duration, treatment spot size, placement, and pattern reportedly affect the accommodative and refractive effect.
U.S. Pat. No. 7,655,002 relates to methods for the creation of microspheres to treat the clear, intact crystalline lens of the eye with energy pulses, such as from lasers, for the purpose of correcting presbyopia, other refractive errors, and for the retardation and prevention of cataracts. Microsphere formation in non-contiguous patterns or in contiguous volumes reportedly works to change the flexure, mass, or shape of the crystalline lens in order to maintain or reestablish the focus of light passing through the ocular lens onto the macular area, and to maintain or reestablish fluid transport within the ocular lens.
U.S. Publication 2005/0165387 relates to surgical lasers and their controllers as well as methods for the treatment of an eye lens, especially for the treatment of presbyopia.
U.S. Publications 2007/0173795, 2007/0185475, 2010/0004643 and WO 2007/084694 relate to a system and apparatus for reportedly increasing the amplitude of accommodation and/or changing the refractive power and/or enabling the removal of the clear or cataractous lens material of a natural crystalline lens. Generally, the system comprises a laser, optics for delivering the laser beam, and a control system for delivering the laser beam to the lens in a particular pattern. There is further provided apparatus for determining the shape and position of the lens with respect to the laser. There is yet further provided a method and system for delivering a laser beam in the lens of the eye in a predetermined shot pattern.
U.S. Publication 2011/0118712 relates to an ophthalmologic laser system comprising an ultra-short pulse laser for outputting ultra-short laser pulses, focusing optics for producing at least one focal point on and/or in the eye lens of the patient's eye, a deflection mechanism for varying the position of the focal point on and/or in the eye lens, and comprising a control mechanism for controlling the deflection mechanism. The laser system is characterized in that the laser pulses output by the ultra-short pulse laser and the size of the focal point fixed by the focusing optics are configured such that a fluence can be applied below or on the disruption threshold of the material of the eye lens at the focal point wherein said fluence is at the same time sufficiently high to reportedly cause changes in at least one material property of the material of the eye lens. The laser system is also characterized in that the deflection unit can be reportedly actuated by means of the control mechanism in such a way that the focal points of a group of laser pulses are arranged such that a diffractive optical structure can be produced by the changes in the material property in the eye lens caused by way of application of the laser pulses. The invention also relates to a method for generating control data for actuating a deflection unit of such a laser system.
U.S. Publication 2011/0184392 relates to a method of treating a lens of a patient's eye that includes generating a light beam, deflecting the light beam using a scanner to form a treatment pattern of the light beam, delivering the treatment pattern to the lens of a patient's eye to create a plurality of cuts in the lens in the form of the treatment pattern to break the lens up into a plurality of pieces, and removing the lens pieces from the patient's eye. The lens pieces can then be mechanically removed. The light beam can be used to create larger segmenting cuts into the lens, as well as smaller softening cuts that soften the lens for easier removal.
Additional methods and devices for correcting various vision conditions are set forth in Novel Approaches to Correction of Presbyopia with Laser Modification of the Crystalline Lens, Myers et al., J. Refract. Surg. 14(2), 136-139 (1998); Femtosecond Laser Induced Flexibility Change of Human Donor Lenses, Schumacher et al. Vis. Res. 49(14), 1853-1859 (2009); Experimental Increase in Accommodative Potential after Neodymium: Yttrium-Aluminum-Garnet Laser Photodisruption of Paired Cadaver Lenses, Krueger et al., Ophthalmology 108 (11), 2122-2129 (2001); First Safety Study of Femtosecond Laser Photodisruption in Animal Lenses: Tissue Morphology and Cataractogenesis, Krueger et al., J. Cataract Refract. Surg. 31(12), 2386-2394 (2005); Fs-Laser Induced Elasticity Changes to Improve Presbyopic Lens Accommodation, Ripken et al., Graefe's. Arch. Clin. Exp. Ophthalmol. (2008) 246:897-906; and Femtosecond Laser Photodisruption of the Crystalline Lens for Restoring Accommodation, Mello et al. International Ophthalmology Clinics 51 (2), 87-95 (2011).
In view of the above, there still remains a need to provide methods and laser ablation patterns that are used to reduce the force needed to change the three dimensional morphology of the human lens and further increase its amplitude of accommodation.